Final answer:
The verb form used to indicate the perfect progressive tense is 'have been verb -ing'. This form shows an action that started in the past and either continues to the present or was ongoing in the past. 'have been' is combined with the present participle (verb + -ing) to construct this tense.
Step-by-step explanation:
The verb form used to indicate the perfect progressive tense is 'have been verb -ing' (option C). This tense is used to show that an action started in the past and has continued up to the present time or was happening continuously over a period of time in the past. For instance, 'I have been reading for hours' indicates that the action of reading started in the past and is still ongoing or just recently finished. The key components of the perfect progressive tense are the auxiliary verbs 'have been' followed by the present participle of the main verb (verb + -ing).
The suffix -ed adds the meaning 'in the past' or 'action completed' to verbs, and depending on the verb, it may be pronounced as [d]. However, this form is associated with the simple past and the past participle of regular verbs, not the perfect progressive tense. The past tense forms that end in -t are irregular past tense forms of certain verbs, and while interesting, they do not help in forming the perfect progressive tense.
In the context of passive voice, the form of the be verb (am, is, are, was, were) appears with a past participle. This structure shows that the subject of the sentence is being acted upon rather than performing the action. While this is related to verb forms, it refers to voice rather than tense.